Raman spectroscopy ofRuSr2GdCu2O8

Raman scattering study ofRuSr2R2−xCexFainstein1, Pregliasco2, Williams3 et al. 2002Phys. Rev. BSelf Cite10030View full textAdd to dashboardCite

“…We note that similar features have been observed previously for RuGd1212. [15][16][17] We have observed from a detailed study in RuGd1212 sintered samples that the diffusive contribution displays, in addition to the usual Bose-factor temperature dependence, an abrupt decrease at T M . 23 In addition, we found 17 a kind of sum rule that connects the intensity of the ϳ130 cm Ϫ1 peak and the diffusive scattering, pointing into a common origin for the two features.…”

“…RuO 6 rotations and involving these atoms have been reported. [15][16][17][18] In view of the many possible Raman active modes and in order to analyze the spectra we consider the following approach. First, we expect that the most intense modes correspond to those already active for the undistorted structure.…”

“…The symmetry of this mode has been derived from polarization resolved measurements in oriented thin films. 17 We recall that this mode is allowed in RuR 1212 and RuR 1222 only when the symmetry reduction due to rotations of the RuO 6 octahedra is taken into account. We note that the strongest line observed for ϭ514.5 nm excitation is the O͑Sr͒ z-polarized vibration in accordance with previous results on RBa 2 Cu 3 O 7 and RuR 1212 .…”

“…Within the resolution of the neutron powder diffraction experiments, however, the only structural parameters that seem to respond to the magnetic ordering at T M are the distance between the two CuO 2 layers and the buckling angle of the CuO 2 planes. 14 This surprising result is also intriguing in view of the Raman scattering data [15][16][17][18] reported for RuR 1212 which display notable changes at T M , including the appearance of a low-energy peak reminiscent of a structural transition related soft mode. 19 We report here a Raman scattering study of polycrystalline samples of the related magnetic superconducting ruthenocuprate RuSr 2 R 2Ϫx Ce x Cu 2 O 10ϩ␦ ͓RuR(2Ϫx) 1222 , R ϭGd,Eu].…”

Effect of Cation Substitution on the Lattice Vibration and Crystal Structure of Magnetic RuSr1.9A0.1GdCu2O8(A = Ca, Sr, and Ba) Superconductors

“…To verify this speculation, micro-Raman spectroscopy would be one of the most suitable tools because of its sensitivity to local structural distortion as well as to variation of chemical bond strength. [11][12][13][14][15] In this work, we have carried out micro-Raman spectroscopic lonic radius of substituent (Å) c -axis lattice parameter ( Å) analysis for the alkaline earth metal-substituted RuSr1.9A0.1 GdCu 2 O 8 (A = Ca, Sr, and Ba) to probe the effects of the cation substitution on the lattice vibration and crystal structure of the ruthenocuprate. The origin of Tc evolution upon the Ca/Ba substitution was discussed on the basis of the obtained information on the accompanying local structural modification.…”